Extended Data Fig. 2: Cable bus characterization.
From: A high-efficiency elementary network of interchangeable superconducting qubit devices
a, Setup used to probe the modes of the coaxial cable in a reflection measurement. The inner conductor of the cable protrudes into a tunnel in the modules and capacitively couples to a pin connected to the SMA flange. b, CAD drawing of one of the cable modules. Top half has been made transparent to show the cable inner conductor (green) and coupling pin (gold) inside. c, Example reflection measurements of 3λ/2 modes of two cables (left: NbTi cable; right: Al cable) obtained with a vector network analyser; only phase response shown here. Fits (solid lines) to the data yield Qb = 3 × 104 (NbTi) and 5 × 105 (Al).
